Background: Transurethral resection of the prostate (TURP) remains the gold-standard surgical treatment for medically refractory symptoms of benign prostatic hyperplasia (BPH), a condition that is symptomatic in approximately 5.6 million men in the United States alone. There is great concern in the Urological community that the training and assessment of the skills necessary to perform TURP may be inadequate. With an overall research mission statement to enhance proficiency and diminish operative errors through the design, development, validation and dissemination of novel training systems for medical procedures, the primary goal of this project is to examine predictive validity of a novel virtual reality TURP trainer built at the University of Washington. This simulator has already undergone preliminary validation studies. Direct evidence of translation of skills from the virtual world to the operating room is lacking and needs to occur prior to implementation of simulation technology into the residency curriculum. We hypothesize that practicing on this trainer will lead to diminished errors and increased proficiency among cohorts of surgeons in training (residents). Methods: 90 Urology residents in training from eight institutions will undergo evaluation at their home institution by the Global Surgical Assessment forms on four sequential TURP cases. These cases will also be video-taped, and the median bar component of the case will be assessed by three blinded subject matter experts. Intraoperative metrics contributing to "performance" will also be collected and consist of time to task, tissue resected, number of cuts, blood loss, irrigation use and errors performed. Between cases 2 and 3, half of the residents (randomized within groups sorted by institution and skill-level) will undergo intensive 2 day training on the UW TURP trainer to criterion-level. Similar metrics as taken from the OR will be collected from a full pre-training and post-training TURP on the simulator and correlated with intraoperative metrics. Improvements in performance and number of operative errors will be compared between those residents who trained on the simulator and those who did not.